Wellbore servicing composition with controlled gelation of cement kiln dust and methods of making and using same

ABSTRACT

Provided here are a wellbore servicing composition, methods of making same, and methods of servicing a wellbore penetrating a subterranean formation using same. The wellbore servicing composition comprises cement kiln dust (CKD), an organic acid, and water. A method of servicing a wellbore penetrating a subterranean formation comprises placing the wellbore servicing composition into the wellbore. The wellbore servicing composition can be used as a spacer fluid in a wellbore servicing operation.

BACKGROUND

This disclosure relates to servicing a wellbore. More specifically, itrelates to servicing a wellbore with fluids comprising cement kiln dust(CKD), an organic acid, and water.

Natural resources such as gas, oil, and water residing in a subterraneanformation or zone are usually recovered by drilling a wellbore down tothe subterranean formation while circulating a drilling fluid in thewellbore. After terminating the circulation of the drilling fluid, astring of pipe (e.g., casing) is run in the wellbore. The drilling fluidis then usually circulated downward through the interior of the pipe andupward through the annulus, which is located between the exterior of thepipe and the walls of the wellbore. Next, a train of fluids, including aspacer or an efficiency fluid, can be placed though the interior of thepipe and upward into the annulus to displace a portion of the existingfluid in the annulus, in order to separate the drilling fluid from thecementing fluid and prepare the wellbore to receive the cementing fluid.After that, primary cementing is typically performed whereby a cementslurry is placed in the annulus and permitted to set into a hard mass(i.e., sheath) to thereby attach the string of pipe to the walls of thewellbore and seal the annulus. Subsequent secondary cementing operationsmay also be performed.

Cement kiln dust, or CKD, is a material that can be included in wellboreservicing fluids such as spacer fluids or cementitious fluids. Forexample, CKD can be used to increase the strength development ofPortland cements or as a pozzolanic type material in cementitiouscompositions. Although the use of CKD is fairly common, there are someinherent challenges associated with CKD such as source to sourcevariability in composition and performance properties. Of the variationspossible with different CKDs, one potential issue relates to theirdiffering gelation behaviors. For example, a CKD from one source may notgel at all when mixed with water, while another may gel strongly.Therefore, there exists a need to address mitigation of this variableCKD gelation during wellbore servicing operations such as cementing toincrease service quality, improve flowability (pumpability) of fluidscomprising CKD, mitigate risks of premature end of job due togelation-associated problems, and to address other issues related to CKDgelation.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and theadvantages thereof, reference is now made to the following briefdescription, taken in connection with the accompanying drawings anddetailed description, wherein like reference numerals represent likeparts.

FIG. 1 shows the comparison of Lafarge CKD gelation with high retarderconcentrations.

FIG. 2 shows the comparison of Holcim CKD gelation with high retarderconcentrations.

FIG. 3 shows the ultrasonic cement analyzer (UCA) chart of a CKD slurrywith a high concentration of tartaric acid.

DETAILED DESCRIPTION

It should be understood at the outset that although an illustrativeimplementation of one or more embodiments are provided below, thedisclosed systems and/or methods may be implemented using any number oftechniques, whether currently known or in existence. The disclosureshould in no way be limited to the illustrative implementations,drawings, and techniques illustrated below, including the exemplarydesigns and implementations illustrated and described herein, but may bemodified within the scope of the appended claims along with their fullscope of equivalents.

Disclosed herein are wellbore servicing fluids (also referred to aswellbore servicing compositions or wellbore compositions) comprisingcement kiln dust (CKD), an organic acid, and water, and referred tocollectively herein as CKD fluids. In some embodiments, the CKD fluidscan further comprise one or more cementitious materials as well as otheradditives. The CKD fluids of the type described herein can be placed ina wellbore as part of a wellbore servicing operation, including withoutlimitation drilling and/or cementing operations. Examples of the CKDfluids include, but are not limited to, spacer fluids, efficiency fluid,cementing fluid, etc. In some embodiments, one or more CKD fluids of thetype disclosed herein are used in a wellbore cementing operation, forexample as a spacer fluid, as a component in a cementitious composition,or both.

The CKD fluid comprises cement kiln dust (CKD). CKD is a fine powderymaterial similar in appearance to Portland cement. There are two typesof cement kiln processes: wet-process kilns, which accept feed materialsin a slurry form; and dry-process kilns, which accept feed materials ina dry, ground form. In each type of process the dust can be collectedand processed in two ways: (1) a portion of the dust can be separatedand returned to the kiln from the dust collection system (e.g., cyclone)closest to the kiln, or (2) the total quantity of dust produced can berecycled or discarded. The chemical and physical characteristics of CKDthat is collected for use outside of the cement production facility willdepend in great part on the method of dust collection employed at thefacility.

In embodiments, the CKD contains analytical CaO in an average amount ofabout 65 wt. % by weight of the CKD, in an amount of from about 30 wt. %to about 90 wt. % by weight of the CKD, alternatively from about 50 wt.% to about 80 wt. %, alternatively from about 60 wt. % to about 70 wt.%; analytical SiO₂ in an average amount of about 18 wt. % by weight ofthe CKD, in an amount of from about 0 wt. % to about 30 wt. % by weightof the CKD, alternatively from about 5 wt. % to about 27 wt. %,alternatively from about 10 wt. % to about 25 wt. %; analytical Al₂O₃ inan average amount of about 3 wt. % by weight of the CKD, in an amount offrom about 0 wt. % to about 12 wt. % by weight of the CKD, alternativelyfrom about 0 wt. % to about 10 wt. %, alternatively from about 0 wt. %to about 6 wt. %. In embodiments, the CKD has a specific gravity (SG) offrom about 2.6 to about 3.2. In embodiments, the average SG is about2.8. In some embodiments, the CKD has a bulk density (BD) of from about33 lb/ft³ to about 84 lb/ft³. In embodiments, the average BD is about 50lb/ft³. In some embodiments, the CKD has a water requirement (WR) offrom about 21 wt. % to about 100 wt. %. WR refers to an amount of mixingwater, based on the weight of the dry CKD, that is needed to form aspecified CKD fluid (e.g., a pumpable slurry having a target densityand/or rheology). In embodiments, the average WR is about 65 wt. % basedon the weight of the dry CKD.

In some embodiments, the CKD is present in the CKD fluid, for example aspacer fluid, in an amount of from about 0.001 wt. % to about 99 wt. %based on the total solid weight of the CKD fluid, alternatively fromabout 0.01 wt. % to about 60 wt. %, alternatively from about 0.04 wt. %to about 40 wt. % based on the total solid weight of the CKD fluid.

In some embodiments, the CKD is present in the CKD fluid, for example acementitious composition, in an amount of from about 0.001 wt. % toabout 75 wt. % based on the total solid weight of the CKD fluid,alternatively from about 0.01 wt. % to about 50 wt. %, alternativelyfrom about 0.04 wt. % to about 25 wt. % based on the total solid weightof the CKD fluid.

The CKD fluid comprises one or more organic acids that may function as agelation retarder or inhibitor. The organic acids as disclosed hereincan be carboxylic acid, sulfonic acid, or any other organic compoundwith acidic properties. The organic acid can comprise tartaric acid,citric acid, oxalic acid, gluconic acid, oleic acid, uric acid, maleicacid, fumaric acid, acetic acid, octenyl succinic acid, dodecenylsuccinic acid, aminotrismethylenephosphonic acid (ATMP), lactic acid,formic acid, oxalic acid, glyoxylic acid, glycolic acid, uric acid,amino acid, propionic acid, butyric acid, phthalic acid, malonic acid,oxaloacetic acid, benzoic acid, glucuronic acids, acrylic acid, malonicacid, tartronic acid, mesoxalic acid, dihydroxymalonic acid, pyruvicacid, hydracrylic acid, glyceric acid, glycidic acid, isobutyric acid,acetoacetic acid, malic acid, crotonic acid, valeric acid, iso-valericacid, glutaric acid, oxoglutaric acid, caproic acid, adipic acid,pyrocitric acid, isocitric acid, sorbic acid, enanthic acid, pimelicacid, salicylic acid, cinnamic acid, caprylic acid, phthalic acid,pelargonic acid, trimesic acid, carpric acid, sebacic acid, orcombinations thereof. In some embodiments, the organic acid is tartaricacid, citric acid, oxalic acid, gluconic acid, oleic acid, uric acid,maleic acid, fumaric acid, acetic acid, octenyl succinic acid, dodecenylsuccinic acid, aminotrismethylenephosphonic acid (ATMP), or acombination thereof.

In some embodiments, the organic acid as disclosed herein may be used atbottomhole circulating temperatures (BHCTs) in the range of from about50° F. to about 500° F.; alternatively from about 100° F. to about 350°F.; alternatively from about 140° F. to about 220° F.

In some embodiments, the organic acid as disclosed herein is present inthe CKD fluid, for example a spacer fluid, in an amount of from about0.01 wt. % to about 10 wt. % based on the total solid weight of the CKDfluid, alternatively from about 0.1 wt. % to about 6 wt. %,alternatively from about 0.25 wt. % to about 3 wt. % based on the totalsolid weight of the CKD fluid. In some embodiments, the ratio of theweight of the organic acid to CKD in the CKD fluid, for example a spacerfluid, is in a range of from about 1% to about 4%.

In some embodiments, the organic acid as disclosed herein is present inthe CKD fluid, for example a cementitious composition, in an amount offrom about 0.01 wt. % to about 7.5 wt. % based on the total solid weightof the CKD fluid, alternatively from about 0.1 wt. % to about 5 wt. %,alternatively from about 0.25 wt. % to about 3 wt. % based on the totalsolid weight of the CKD fluid. In some embodiments, the ratio of theweight of the organic acid to CKD in the CKD fluid, for example acementitious composition, is in a range of from about 0.5% to about 4%.

The CKD fluid comprises water. In some embodiments, the water asdisclosed herein can be selected from the group consisting offreshwater, seawater, saltwater, or brines (e.g., natural brines,formulated brines, etc.), and any combination thereof. The formulatedbrines may be produced by dissolving one or more soluble salts in water,a natural brine, or seawater. Representative soluble salts include thechloride, bromide, acetate, and formate salts of potassium, sodium,calcium, magnesium, and zinc. Generally, the water may be from anysource, provided that it does not contain an amount of components thatmay undesirably affect the other components in the CKD fluid. The watermay be present in the CKD fluid in an amount to form a pumpable fluid orslurry capable of being placed (e.g., pumped) into the wellbore. Thewater may be present in the CKD fluid in an amount effective to providea pumpable fluid or slurry having desired (e.g., job or servicespecific) rheological properties such as density, viscosity, gelstrength, yield point, etc. In some embodiments, the weight ratio of thewater to the solid compositions in the CKD fluid, for example a spacerfluid or a cementitious fluid, can be in a range from about 0.5:1 toabout 7:1.

In some embodiments, the CKD fluid further comprises a cementitiousmaterial, also referred to herein as a cementitious CKD fluid or a CKDcement composition. In some embodiments, the cementitious material asdisclosed herein comprises calcium, aluminum, silicon, oxygen, iron,and/or sulfur. In some embodiments, the cementitious material asdisclosed herein comprises Portland cement, pozzolana cement, gypsumcement, shale cement, acid/base cement, phosphate cement, high aluminacontent cement, slag cement, silica cement, high alkalinity cement,magnesia cement, or combinations thereof. In embodiments, the Portlandcements that are suited for use in the disclosed CKD fluid include, butnot limited to, Class A, C, G, H, low sulfate resistant cements, mediumsulfate resistant cements, high sulfate resistant cements, orcombinations thereof. The class A, C, G, H, are classified according toAPI Specification 10.

In embodiments, the cementitious material is present in the cementitiousCKD fluid in an amount of from about 0.001 wt. % to about 99 wt. % basedon the total solid weight of the cementitious CKD fluid, alternativelyfrom about 0.01 wt. % to about 75 wt. %, alternatively from about 0.01wt. % to about 50 wt. %, alternatively from about 15 wt. % to about 75wt. %, alternatively from about 25 wt. % to about 60 wt. %,alternatively from about 25 wt. % to about 50 wt. %.

In some embodiments, the CKD fluid further comprises a supplementarycementitious material (SCM). Herein, an SCM refers to any inorganicmaterial that is introduced to the fluid in order to increase the volumeof the fluid (for example to lower the consumption of binder materialsuch as Portland cement in a cementitious CKD fluid). In someembodiments, such SCMs may improve one or more properties of the fluidin which it is included. Examples of SCMs suitable for use in thisdisclosure include without limitation ASTM Class F fly ash, Class C flyash, sand, shale, silica, zeolite, metakaolin, or combinations thereof.

In an embodiment, the SCM comprises ASTM Class F Fly ash. Class F flyash comprises residues generated in the combustion of coal, typicallyproduced from the burning of harder, older anthracite and bituminouscoal. Typically, Class F fly ash contains less than about 10% lime.Unlike Class C fly ash, Class F fly ash does not react and harden withwater by itself. In an embodiment, the SCM may be present in the CKDfluid, e.g., cementitious CKD fluid, in an amount of from about 0.001wt. % to about 75 wt. % of total weight of the solid composition of theCKD fluid, alternatively from about 0.01 wt. % to about 50 wt. %, oralternatively from about 0.04 wt. % to about 25 wt. %.

In some embodiments, the CKD fluid further comprises one or moreadditives. In some embodiments, additives may be included in the CKDfluid for improving or changing the properties thereof. Examples of suchadditives include but are not limited to, a weight reducing additive, aheavyweight additive, a lost circulation material, a filtration controladditive, a dispersant, a suspending agent, an expansion additive, anaccelerator, a defoamer, a foaming surfactant, a fluid loss agent, aformation conditioning agent, hollow glass or ceramic beads, orcombinations thereof. Other mechanical property modifying additives, forexample, elastomers, carbon fibers, glass fibers, metal fibers, mineralsfibers, and the like can be added to further modify the mechanicalproperties. These additives may be included singularly or in combinationand in amounts effective to provide a user designated property of theCKD fluid.

In embodiments, the additive may be present in the CKD fluid in anamount of from about 0.001 wt. % to about 25 wt. % of the total weightof the solid composition of the CKD fluid, alternatively from about 0.01wt. % to about 10 wt. %, alternatively from about 0.04 wt. % to about 5wt. %.

In embodiments, the CKD fluid, for example a spacer fluid, has a densityin a range of from about 4 lb/gal to about 18 lb/gal, alternatively fromabout 7 lb/gal to about 16 lb/gal, alternatively from about 9 lb/gal toabout 14 lb/gal. In embodiments, the CKD fluid, for example acementitious CKD fluid, has a density in a range of from about 4 lb/galto about 23 lb/gal, alternatively from about 12 lb/gal to about 17lb/gal, alternatively from about 12 lb/gal to about 14 lb/gal.

In embodiments, the CKD fluids of the type disclosed herein are capableof remaining in a pumpable fluid state for equal to or greater thanabout 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, or 24 hours.

In embodiments, the CKD fluid may have a yield point of from about 3lbf/100 ft² to about 40 lbf/100 ft², alternatively from about 7 lbf/100ft² to about 35 lbf/100 ft², alternatively from about 10 lbf/100 ft² toabout 30 lbf/100 ft².

In some embodiments, the CKD fluid, for example a spacer fluid, asdisclosed herein has a gelation rating of equal to or less than 3, wherethe scale is based upon the behavior of a glass rod that is placed intoa homogeneous mixture of the CKD fluid (e.g., comprising CKD, theorganic acid, and water) at 0 to 6 hours after the homogeneous mixtureis made, wherein the weight ratio of the water to the CKD is in a rangeof from about 1.5 to about 2. The scale is: 1, rod falls downimmediately due to no observed gelation; 2, rod falls down immediatelybut at a slower rate than in 1; 3, rod slowly falls down due to obviousgelation; 4, rod very hesitantly leans over or falls and leaves anengraved path due to above average gelation; and 5, rod is fullysupported due to high gelation. In one example, if the rod falls down ata rate of 5 inch per second, the gelation rating is 1; if the rod fallsdown at a rate of 1 inch per second, the gelation rating is 2; if therod falls down at a rate of 0.5 inch per second, the gelation rating is3; if the rod falls down at a rate of 0.2 inch per second, the gelationrating is 4.

In some embodiments, the CKD fluid (e.g., a mixture of the CKD, theorganic acid, and water) as disclosed herein has a rheological gelstrength at room temperature as determined in accordance with API 10B-2of less than or equal to 30 lbf/100 ft² for up to 5 hours after the CKDfluid is made (e.g., components thereof mixed together); wherein theweight ratio of the water to the CKD is from about 1:1 to about 2.5:1,and wherein the weight ratio of the organic acid to the CKD is in arange from about 0.04% to about 2%. Herein the rheological gel strengthis the shear stress measured at low shear rate after a fluid has set atrest for a period of time (e.g., 10 second, 10 minutes, 30 minutes).

In embodiments, the CKD fluid can be made by a method comprising:placing a mixture comprising CKD, an organic acid, and water into acontainer, and blending the mixture until the mixture becomes ahomogeneous fluid. (e.g., a pumpable slurry). The container can be anycontainer that is compatible with the mixture and has sufficient spacefor the mixture. A blender can be used for blending. In someembodiments, the CKD fluid can be prepared at the wellsite. For examplethe solid components of the CKD fluid can be transported to the wellsiteand combined (e.g., mixed/blended) with water located proximate thewellsite to form the CKD fluid. In some embodiments, the solidcomposition of the CKD fluid can be prepared at a location remote fromthe wellsite and transported to the wellsite, and, if necessary, storedat the on-site location. When it is desirable to prepare the CKD fluidon the wellsite, the solid composition of the CKD fluid along withadditional water and optional other additives can be added into acontainer (e.g. a blender tub, for example mounted on a trailer), andthe mixture is then blended until the mixture becomes a homogeneousfluid (e.g., a pumpable slurry). In embodiments, additives may be addedto the CKD fluid during preparation thereof (e.g., during blending)and/or on-the-fly by addition to (e.g., injection into) the CKD fluidwhen being pumped into the wellbore.

Disclosed herein is a method of servicing a wellbore penetrating asubterranean formation, comprising: placing a CKD fluid of the typedescribed herein into the wellbore, wherein the CKD fluid comprises CKD,an organic acid, and water. It is to be understood that “subterraneanformation” encompasses both areas below exposed earth and areas belowearth covered by water such as ocean or fresh water. In embodiments,there can be a conduit (for example a work string, drill string,production tubing, coiled tubing, etc.) extending from the surface andlocated inside the wellbore forming an annular space between theexterior of the conduit and the wellbore wall, and the method asdisclosed herein further comprises: circulating the CKD fluid from thesurface down through the conduit, exiting the conduit and flowing theCKD fluid back to the surface via the annular space between the conduitwall and the wellbore wall. The circulation of the CKD fluid can beachieved by pumping. During circulation, the CKD fluid can carry and/orflush unwanted material (e.g., solids such as filter cake, particulatematerial, drill cuttings, etc. and/or liquids such as drilling ortreatment fluids) inside the wellbore to the surface of the wellbore,thus the circulation can clean up the wellbore. In an embodiment, arelatively high volume of the CKD fluid may be circulated through thewellbore to clean and/or flush the wellbore of unwanted material.

In some embodiments, the CKD fluid is a spacer fluid, and a method ofservicing a wellbore comprises placing (e.g., pumping) a first fluidinto the wellbore, thereafter placing (e.g., pumping) the CKD spacerfluid into the wellbore, and thereafter placing (e.g., pumping) a secondfluid into the wellbore, wherein the CKD spacer fluid physically spacesthe first fluid apart from the second fluid such that the first fluidand the second fluid do not comingle while being placed (e.g., pumped)into the wellbore. For example, the spacer fluid can be used to spaceapart two fluids (e.g., drilling fluid/mud and a cementitiouscomposition) that are being flowed from the surface down through aconduit (e.g., casing) present in the wellbore, exiting the conduit andflowing back upward in the annular space between the outside conduitwall and interior face of the wellbore.

Disclosed herein is a method of servicing a wellbore with casingdisposed therein to form an annular space between the wellbore wall andthe outer surface of the casing, wherein a drilling fluid (or otherfluid) is present in at least a portion of the annular space. Thedrilling fluid herein refers to any liquid and gaseous fluid andmixtures of fluids and solids used in operations of drilling a boreholeinto the earth. The drilling fluid can be water based, non-water based,and/or gaseous. In embodiments, the method disclosed herein comprises:placing a CKD spacer into at least a portion of the annular space anddisplacing at least a portion of the drilling fluid from the annularspace, wherein the CKD spacer comprises CKD, an organic acid, and water,and wherein the density and yield point of the CKD spacer are largerthan the density and yield point of the drilling fluid. Herein the CKDspacer is a spacer fluid. A spacer fluid is used to physically separateone special purpose liquid from another, and a spacer fluid should becompatible with each of the special purpose fluids. In some embodiments,the method disclosed herein further comprises: placing a cementitiousfluid into at least a portion of the annular space and displacing atleast a portion of the CKD spacer from the annular space, wherein thedensity and yield point of the cementitious fluid are larger than thedensity and yield point of the CKD spacer. A cementitious fluid refersto the material used to permanently seal the annular space between thecasing and the wellbore wall. A cementitious fluid can also be used toseal formations to prevent loss of drilling fluid (e.g., in squeezecementing operations) and for operations ranging from setting kick-offplugs to plug and abandonment of a wellbore. Generally, a cementitiousfluid used in oil field is less viscous and has less strength thancement or concrete used for construction, since the cementitious fluidis required to be pumpable in relatively narrow annulus over longdistances. A cementitious fluid is typically prepared by mixing cement,water, and assorted dry and liquid additives. In embodiments, the CKDspacer (e.g., comprising CKD, an organic acid, and water) is used toseparate the drilling fluid from the cementitious fluid.

In embodiments, disclosed herein is a method of servicing a wellborewith casing disposed therein to form an annular space between thewellbore wall and the outer surface of the casing, wherein a drillingfluid (or other fluid) is present in at least a portion of the annularspace. In embodiments, the method disclosed herein comprises: placing aspacer fluid into at least a portion of the annular space and displacingat least a portion of the drilling fluid from the annular space, whereinthe density and yield point of the spacer fluid are larger than thedensity and yield point of the drilling fluid. In some embodiments, themethod disclosed herein further comprises: placing a CKD cementitiousfluid into at least a portion of the annular space and displacing atleast a portion of the spacer fluid from the annular space, wherein thedensity and yield point of the CKD cement fluid are larger than thedensity and yield point of the spacer fluid. Herein the CKD cementitiousfluid comprises CKD, an organic acid, cementitious material, and water.

In embodiments, disclosed herein is a method of servicing a wellborewith casing disposed therein to form an annular space between thewellbore wall and the outer surface of the casing, wherein a drillingfluid (or other fluid) is present in at least a portion of the annularspace. In embodiments, the method disclosed herein comprises: placing aCKD spacer into at least a portion of the annular space and displacingat least a portion of the drilling fluid from the annular space, whereinthe density and yield point of the CKD spacer are larger than thedensity and yield point of the drilling fluid. Herein the CKD spacercomprises CKD, an organic acid, and water. In some embodiments, themethod disclosed herein further comprises: placing a CKD cementitiousfluid into at least a portion of the annular space and displacing atleast a portion of the CKD spacer from the annular space, wherein thedensity and yield point of the CKD cementitious fluid are larger thanthe density and yield point of the CKD spacer. Herein the CKDcementitious fluid comprises CKD, an organic acid, cementitiousmaterial, and water.

In embodiments, the method disclosed herein further comprises placing aCKD fluid into at least a portion of the tubular space inside thecasing; and displacing at least a portion of the cementitious fluid orCKD cementitious fluid from the tubular space. For example, a CKD fluidof the type described herein can be pumped into the wellbore followingrelease of a cement plug, and the CKD fluid can be used to push thecement plug through the casing, which in turn pushes the cementitiousfluid (e.g., CKD cementitious fluid) out of the casing and into theannular space between the casing and the wellbore wall.

In some embodiments, the methods disclosed herein further compriseallowing the spacer fluid (e.g., the CKD spacer) to gel and/or set. Insome embodiments, the methods disclosed herein further comprise allowingthe cementitious fluid (e.g., the CKD cementitious fluid) to set.

EXAMPLES

The embodiments having been generally described, the following examplesare given as particular embodiments of the disclosure and to demonstratethe practice and advantages thereof. It is understood that the examplesare given by way of illustration and are not intended to limit thespecification or the claims in any manner.

The following examples show the mitigation of CKD fluid gelation throughthe use of organic acids. Two CKDs from different vendors and withdiffering physicochemical properties (Table 1) were selected to betested. Several retarder types and loadings were mixed with these CKDsto determine their effectiveness for gel mitigation of CKD fluids of thetype disclosed herein.

TABLE 1 Physicochemical characteristics of CKDs SG BD WR SiO₂ CaOLafarge CKD (Midlothian, TX) 2.99 63.2 91 21.4 65.2 Holcim CKD (Ada, OK)2.85 42.7 83 30.2 53.3

Example 1

A commonly used CKD from Lafarge's Midlothian, Tex. facility was chosento determine the effectiveness of several types of retarders on slowingdown gelation behavior of the CKD fluid of the type disclosed herein.

The CKD was dry blended with either no retarder as a control, highconcentration of retarder (2% by weight of the CKD) or low concentrationof retarder (0.4% by weight of the CKD). The formulations are summarizedin Table 2 below.

TABLE 2 Formulations of Lafarge CKD slurries including differentretarder concentrations High Low Material Name Control ConcentrationConcentration CKD (g) 200 200 200 Water (g) 400 400 400 RetarderConcentration (g) 0 4.0 0.8

The dry blend was added to the water and this mixture was hand mixedwith a glass rod until homogeneity was achieved. The slurry was thenpoured into a 200 mL Tri-Pour® beaker and rheological observations weremade and recorded using the observational scale below.

Observational Scale:

The scale is based upon the behavior of a glass rod that has been placedinto the slurry:

1—rod falls down immediately due to no observed gelation; 2—rod fallsdown immediately but at a slower rate than in 1; 3—rod slowly falls downdue to obvious gelation; 4—rod very hesitantly leans over or falls andleaves an engraved path due to above average gelation; and 5—rod isfully supported due to high gelation.

Table 3 below summarizes the results of this testing. It appears that atthe low concentration, no significant reduction in gelation occurs forany of the retarder types.

TABLE 3 Tabulated observations of Lafarge CKD gelation behavior withvarious retarders Malto- Ligno- AMPS Tartaric Citric dextrin sulfonateco-polymer Acid Acid ATMP* Time Low High Low High Low High Low High LowHigh Low High (min) Control Conc. Conc. Conc. Conc. Conc. Conc. Conc.Conc. Conc. Conc. Conc. Conc. 0 1 1 1 1 1 1 1 1 1 1 1 1 1 150 2 2 3 3 43.5 4 4 1.5 2.5 1.5 2.5 1.5 300 2.5 3.5 4 3.8 4 3.8 4 4 1 3.8 1 3.5 1360 3 3 3 3.8 4 3.8 4 4 1 3.8 1 3.5 1 *aminotrismethylenephosphonic acidAMPS is a copolymer of 2-acrylamido-2methy1 propane sulfonate andacrylamide.

However, as seen in FIG. 1, at higher retarder loading, the organicacids (e.g., tartaric acid, citric acid, and ATMP) prevent gelation ofthe CKD fluid not only initially (time=0) but over extended periods oftime (up to 6 hours).

Conversely, as seen in FIG. 1, other retarder types such as maltodextrin(sugar type retarders), lignosulfonate, and synthetic retarders (AMPS)actually increase the amount of gelation relative to the control.

Example 2

As verification that this phenomenon holds true for various CKD sources,a second experiment was performed with a CKD sourced from Holcim's Ada,Okla. facility. Although the water content of the slurries was adjustedslightly, the same formulations and procedures as in Example 1 wererepeated. The formulations are shown in Table 4 below.

TABLE 4 Formulations of Holcim CKD slurries including different retarderconcentrations High Low Material Name Control ConcentrationConcentration CKD (g) 200 200 200 Water (g) 312 312 312 RetarderConcentration (g) 0 4.0 0.8

The same observational scale was used to rate the effectiveness of theretarders in gelation pacification. Table 5 below summarizes the resultsof this testing.

TABLE 5 Tabulated observations of Holcim CKD gelation behavior withvarious retarders Malto- Ligno- AMPS Tartaric Citric dextrin sulfonateco-polymer Acid Acid ATMP Time Low High Low High Low High Low High LowHigh Low High (min) Control Conc. Conc. Conc. Conc. Conc. Conc. Conc.Conc. Conc. Conc. Conc. Conc. 0 1 1 1 1 1 1 1 1 1.5 1 1.25 1 1 10 4 43.5 4 1 4 1.25 1 1 1 1 4 2 40 4 4 4 4 4 4 4 4 2 2 1 4 2 60 4 4 4 4 4 4 44 2 4 1 4 4 360 4 4 4 4 4 4 4 4 3.75 4 3 4 4

Similar to the CKD fluids comprising the Lafarge Midlothian, Tex. CKD,low retarder concentrations have minimal effect on the gelation behaviorof CKD fluids comprising the Holcim Ada, Okla. CKD.

For high concentration of retarder, as detailed in FIG. 2, citric acidwas the most effective gel mitigator, outperforming the control at alltime intervals. Tartaric acid and ATMP also performed well until about60 minutes after which time the gelation increased back to controllevels. This time dependence of performance indicates that most likelyhigher concentrations of Tartaric and ATMP are required to preventgelation over long time frames. Again, the other retarder types seemedto enhance gelation of the CKD.

As can be seen from the results of both Examples 1 and 2, the organicacid retarder types mitigated CKD gelation much more effectively thanthe other types.

Example 3

To obtain a more quantitative result, rheological gel strength testingwas performed on the same CKD fluid as Example 2 (e.g., comprisingHolcim Ada, Okla. CKD) with varying amounts of retarder. The samecontrol and 2% retarder concentration formulations were tested. Theblends were mixed together with water in a waring blender for 35 secondsat 4000 RPM and gel strength was performed on a FANN 35 viscometer. The10 second and 30 minute gel strengths were recorded at room temperaturein accordance with the procedure set forth in API 10B-2.

TABLE 6 Gel strength measurements of various retarders 10 second max. 30minute max. Concentration Retarder Type dial reading dial reading 0%None 6 >300 2% Lignosulfonate 3 >300 2% Citric Acid 7   7

As can be seen in Table 6, there is a definitive difference in the 30minute gel strength of the control and the slurries with citric acid.The citric acid, at 2% loading, provided gel mitigation throughout theduration of the test. While the lignosulfonate may have provided someinitial dispersion, after 30 minutes the gel strength was no differentthan the control.

To further expand on the results from Table 6, the slurry with 2% citricacid was run again, this time for a 5 and 8 hour gel times. The resultsare shown below as an addition to the previous data.

TABLE 7 Gel Strength measurements for 2% citric acid treatment 10 secondmax. 5 hour max. 8 hour max. dial reading dial reading dial reading 7 1571

The results from Table 7 show how the citric acid treatment inhibitsgelation for a finite amount of time. Therefore, with the addition ofcitric acid, CKD fluids (e.g., slurries) can be tuned to stave ofgelation for a limited amount of time before building gel strength. Thisis relevant for fluid (e.g., slurry) placement during field operationsand allows for a range of tunable solutions for customers.

Example 4

A CKD slurry with tartaric acid as the retarder was prepared, using thesame formulation of the high concentration retarder dosage in Table 4.The CKD slurry was mixed in a waring blender according to API 10B-2. Itwas then conditioned at 140° F. in an atmospheric consistometer for 2hours to simulate placement during field operations. The rheologies werethen recorded as in Table 8.

TABLE 8 Rheologies of CKD slurries with high concentration tartaric acidRPM Dial Reading 3 13 6 16 30 50 60 60 100 66 200 77 300 85 Performedusing a FANN 35 Viscometer with R1B1F1 configuration as in Example 3.

The rheology results above show that the CKD slurry is viable in fieldoperations. For example, in use conditions from a typical West Texaswell, pumping 50 bbl of spacer with this rheological profile in a 5.5inch OD and 4.779 inch ID casing, the pressure drop in the casing is 66psi and in the open hole-casing annulus the pressure drop is 129 psi.These low pressure values show that the CKD mitigation slurry can easilybe pumped in field operations.

Example 5

The same CKD slurry as in EXAMPLE 4 was prepared and put directly intoan ultrasonic cement analyzer (UCA) to determine degree ofconsolidation. The test parameters consisted of a temperature ramp to200° F. in 2 hours and a constant pressure of 3000 psi. As can be seenin the UCA chart in FIG. 3, even though the slurry had a highconcentration of tartaric acid, it eventually consolidates into ahardened mass with an ultrasonic compressive strength of 100 psi inapproximately 7 days.

ADDITIONAL DISCLOSURE

The following are non-limiting, specific embodiments in accordance withthe present disclosure:

A first aspect, which is a wellbore servicing composition comprising:cement kiln dust (CKD), an organic acid, and water.

A second aspect, which is the wellbore servicing composition of thefirst aspect, wherein the CKD contains analytical CaO in an amount offrom about 30 wt. % to about 90 wt. % by weight of the CKD, analyticalSiO₂ in an amount of from about 0 wt. % to about 30 wt. % by weight ofthe CKD, analytical Al₂O₃ in an amount of from about 0 wt. % to about 12wt. % by weight of the CKD.

A third aspect, which is the wellbore servicing composition of the firstor the second aspect, wherein the CKD has a specific gravity (SG) offrom about 2.6 to about 3.2.

A fourth aspect, which is the wellbore servicing composition of any ofthe first to the third aspects, wherein the CKD has an average SG ofabout 2.8.

A fifth aspect, which is the wellbore servicing composition of any ofthe first to the fourth aspects, wherein the CKD has a bulk density (BD)of from about 33 lb/ft³ to about 84 lb/ft³.

A sixth aspect, which is the wellbore servicing composition of any ofthe first to the fifth aspects, wherein the CKD has an average BD ofabout 50 lb/ft³.

A seventh aspect, which is the wellbore servicing composition of any ofthe first to the sixth aspects, wherein the CKD has a water requirement(WR) of from about 21 wt. % to about 100 wt. %.

An eighth aspect, which is the wellbore servicing composition of any ofthe first to the seventh aspects, wherein the CKD has an average WR ofabout 65 wt. %.

A ninth aspect, which is the wellbore servicing composition of any ofthe first to the eighth aspects, wherein the CKD is present in an amountof from about 0.001 wt. % to about 99 wt. % based on the total solidweight of the wellbore servicing composition.

A tenth aspect, which is the wellbore servicing composition of any ofthe first to the ninth aspects, wherein the organic acid comprisestartaric acid, citric acid, oxalic acid, gluconic acid, oleic acid, uricacid, maleic acid, fumaric acid, acetic acid, octenyl succinic acid,dodecenyl succinic acid, aminotrismethylenephosphonic acid (ATMP),lactic acid, formic acid, oxalic acid, glyoxylic acid, glycolic acid,uric acid, amino acid, propionic acid, butyric acid, phthalic acid,malonic acid, oxaloacetic acid, benzoic acid, glucuronic acids, acrylicacid, malonic acid, tartronic acid, mesoxalic acid, dihydroxymalonicacid, pyruvic acid, hydracrylic acid, glyceric acid, glycidic acid,isobutyric acid, acetoacetic acid, malic acid, crotonic acid, valericacid, iso-valeric acid, glutaric acid, oxoglutaric acid, caproic acid,adipic acid, pyrocitric acid, isocitric acid, sorbic acid, enanthicacid, pimelic acid, salicylic acid, cinnamic acid, caprylic acid,phthalic acid, pelargonic acid, trimesic acid, carpric acid, sebacicacid, or combinations thereof.

An eleventh aspect, which is the wellbore servicing composition of anyof the first to the tenth aspects, wherein the organic acid comprisetartaric acid, citric acid, aminotrismethylenephosphonic acid (ATMP), orcombinations thereof.

A twelfth aspect, which is the wellbore servicing composition of any ofthe first to the eleventh aspects, wherein the organic acid may be usedat bottomhole circulating temperatures (BHCTs) in the range of fromabout 50° F. to about 500° F.

A thirteenth aspect, which is the wellbore servicing composition of anyof the first to the twelfth aspects, wherein the organic acid is presentin an amount of from about 0.01 wt. % to about 10 wt. % based on thetotal solid weight of the wellbore servicing composition.

A fourteenth aspect, which is the wellbore servicing composition of anyof the first to the thirteenth aspects, wherein the ratio of the weightof the organic acid to CKD is in a range of from about 0.5% to about 4%.

A fifteenth aspect, which is the wellbore servicing composition of anyof the first to the fourteenth aspects, wherein the water compriseswater selected from the group consisting of freshwater, saltwater,brine, seawater, and any combination thereof.

A sixteenth aspect, which is the wellbore servicing composition of anyof the first to the fifteenth aspects, wherein the ratio of the weightof the water to the solid compositions in the wellbore servicingcomposition is in a range from about 0.5:1 to about 7:1.

A seventeenth aspect, which is the wellbore servicing composition of anyof the first to the sixteenth aspects, further comprising a cementitiousmaterial.

An eighteenth aspect, which is the wellbore servicing composition of theseventeenth aspect, wherein the cementitious material comprises Portlandcement, pozzolana cement, gypsum cement, shale cement, acid/base cement,phosphate cement, high alumina content cement, slag cement, silicacement, high alkalinity cement, magnesia cement, or combinationsthereof.

A nineteenth aspect, which is the wellbore servicing composition of anyof the seventeenth to the eighteenth aspects, wherein the cementitiousmaterial is present in an amount of from about 0.001 wt. % to about 99wt. % based on the total solid weight of the wellbore servicingcomposition.

A twentieth aspect, which is the wellbore servicing composition of anyof the first to the nineteenth aspects, further comprising asupplementary cementitious material (SCM).

A twenty-first aspect, which is the wellbore servicing composition ofthe twentieth aspect, wherein the SCM comprises Class F fly ash, Class Cfly ash, sand, shale, silica, zeolite, metakaolin, or combinationsthereof.

A twenty-second aspect, which is the wellbore servicing composition ofany of the twentieth to the twenty-first aspects, wherein the SCM ispresent in an amount of from about 0.001 wt. % to about 75 wt. % oftotal weight of the solid composition of the wellbore servicingcomposition.

A twenty-third aspect, which is the wellbore servicing composition ofany of the first to the twenty-second aspects, further comprising anadditive selected from the group consisting of a weight reducingadditive, a heavyweight additive, a lost circulation material, afiltration control additive, a dispersant, a suspending agent, anexpansion additive, an accelerator, a defoamer, a foaming surfactant, afluid loss agent, latex emulsions, a formation conditioning agent,hollow glass or ceramic beads, elastomers, carbon fibers, glass fibers,metal fibers, minerals fibers, and any combination thereof.

A twenty-fourth aspect, which is the wellbore servicing composition ofthe twenty-third aspect, wherein the additive is present in an amount offrom about 0.001 wt. % to about 25 wt. % of the solid composition of thewellbore servicing composition.

A twenty-fifth aspect, which is the wellbore servicing composition ofany of the first to the twenty-fourth aspects has a density in a rangeof from about 4 lb/gal to about 23 lb/gal.

A twenty-sixth aspect, which is the wellbore servicing composition ofany of the first to the twenty-fifth aspects is capable of remaining ina pumpable fluid state for at least about 4 hours.

A twenty-seventh aspect, which is the wellbore servicing composition ofany of the first to the twenty-sixth aspects has a gelation rating ofequal to or less than 3, where the scale has a value of 1 to 5 basedupon the behavior of a glass rod that is placed into a homogeneousmixture of the CKD, the organic acid, and water at 0 to 6 hours afterthe homogeneous mixture is made, wherein the weight ratio of the waterto the CKD is in a range of from about 1.5 to about 2, and wherein theweight ration of the organic acid to the CKD is in a range from about0.04% to about 2% and wherein the value of 1 to 5 is determined viavisual observation as follows:

-   -   1, rod falls down immediately due to no observed gelation;    -   2, rod falls down immediately but at a slower rate than in 1;    -   3, rod slowly falls down due to obvious gelation;    -   4, rod very hesitantly leans over or falls and leaves an        engraved path due to above average gelation; and    -   5, rod is fully supported due to high gelation.

A twenty-eighth aspect, which is the wellbore servicing composition ofany of the first to the twenty-seven aspects. wherein the rheologicalgel strengths at room temperature as in API 10B-2 of a mixture of theCKD, the organic acid, and water is less than or equal to 30 lbf/100 ft²for up to 5 hours after the mixture is made; wherein the weight ratio ofthe water to the CKD is from about 1:1 to about 2.5:1, and wherein theweight ratio of the organic acid to the CKD is in a range from about0.04% to about 2%.

A twenty-ninth aspect, which is a method of making a wellbore servicingcomposition, comprising: placing a mixture comprising CKD, an organicacid, water, and optionally a cementitious material into a container;and blending the mixture until the mixture becomes a homogeneous fluid.

A thirtieth aspect, which is a method of servicing a wellborepenetrating a subterranean formation, comprising: placing a wellboreservicing composition into the wellbore, wherein the wellbore servicingcomposition comprises CKD, an organic acid, and water.

A thirty-first aspect, which is the method of the thirtieth aspect,wherein the wellbore comprising a conduit disposed therein, wherein theconduit is cylindrical having an inner bore and an outer wall andwherein the method further comprises: circulating the wellbore servicingcomposition downward through the inner bore and upward through anannular space between the outer wall of the conduit and a wall of thewellbore.

A thirty-second aspect, which is the method of any of the thirtieth tothe thirty-first aspects, wherein the wellbore servicing compositionremoves material from the wellbore, thereby cleaning the wellbore.

A thirty-third aspect, which is a method of servicing a wellbore withcasing disposed therein to form annular space between a wellbore walland an outer surface of the casing, wherein a first fluid is present inat least a portion of the annular space, comprising placing a secondfluid into at least a portion of the annular space and displacing atleast a portion of the first fluid from the annular space, wherein thedensity and yield point of the second fluid are larger than the densityand yield point of the first fluid, and placing a third fluid into atleast a portion of the annular space and displacing at least a portionof the second fluid from the annular space, wherein the density andyield point of the third fluid are larger than the density and yieldpoint of the second fluid; wherein the second fluid, the third fluid, orboth of the second fluid and the third fluid comprise cement kiln dust(CKD), an organic acid, and water.

A thirty-fourth aspect, which is the method of the thirty-third aspect,wherein the first fluid is a drilling fluid.

A thirty-fifth aspect, which is the method of the thirty-third or thethirty-fourth aspect, wherein the second fluid is a spacer fluid.

A thirty-sixth aspect, which is the method of the thirty-third, thethirty-fourth, or the thirty-fifth aspect, wherein the third fluid is acementitious fluid.

A thirty-seventh aspect, which is the method of any of the thirty-thirdto the thirty-sixth aspects wherein the second and third fluids arepumped from the surface downward through an inner bore of the casing,exiting a bottom of the casing, and flowing upward through the annularspace.

A thirty-eighth aspect, which is the method of the thirty-seventhaspect, further comprising placing a fourth fluid into at least aportion of the inner bore of the casing; and displacing at least aportion of the third fluid from the inner bore of the casing, whereinthe fourth fluid comprises CKD, and organic acid, and water.

A thirty-ninth aspect, which is the method of any of the thirty-third tothe thirty-eighth aspects, further comprising allowing at least aportion of the second fluid to gel or set.

A fortieth aspect, which is the method of any of the thirty-third to thethirty-ninth aspects, further comprising allowing at least a portion ofthe third fluid to set.

While embodiments have been shown and described, modifications thereofcan be made by one skilled in the art without departing from the spiritand teachings of this disclosure. The embodiments described herein areexemplary only, and are not intended to be limiting. Many variations andmodifications of the embodiments disclosed herein are possible and arewithin the scope of this disclosure. Where numerical ranges orlimitations are expressly stated, such express ranges or limitationsshould be understood to include iterative ranges or limitations of likemagnitude falling within the expressly stated ranges or limitations(e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numericalrange with a lower limit, Rl, and an upper limit, Ru, is disclosed, anynumber falling within the range is specifically disclosed. Inparticular, the following numbers within the range are specificallydisclosed: R=Rl+k* (Ru−Rl), wherein k is a variable ranging from 1percent to 100 percent with a 1 percent increment, i.e., k is 1 percent,2 percent, 3 percent, 4 percent, 5 percent, . . . 50 percent, 51percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98percent, 99 percent, or 100 percent. Moreover, any numerical rangedefined by two R numbers as defined in the above is also specificallydisclosed. Use of the term “optionally” with respect to any element of aclaim is intended to mean that the subject element may be present insome embodiments and not present in other embodiments. Both alternativesare intended to be within the scope of the claim. Use of broader termssuch as comprises, includes, having, etc. should be understood toprovide support for narrower terms such as consisting of, consistingessentially of, comprised substantially of, etc.

Accordingly, the scope of protection is not limited by the descriptionset out above but is only limited by the claims which follow, that scopeincluding all equivalents of the subject matter of the claims. Each andevery claim is incorporated into the specification as an embodiment ofthis disclosure. Thus, the claims are a further description and are anaddition to the embodiments of this disclosure. The discussion of areference herein is not an admission that it is prior art, especiallyany reference that may have a publication date after the priority dateof this application. The disclosures of all patents, patentapplications, and publications cited herein are hereby incorporated byreference, to the extent that they provide exemplary, procedural, orother details supplementary to those set forth herein.

What is claimed is:
 1. A method of servicing a wellbore penetrating asubterranean formation, wherein the wellbore comprises a casing disposedtherein to form annular space between a wellbore wall and an outersurface of the casing and wherein a drilling fluid is present in atleast a portion of the annular space, the method comprising: placing aspacer fluid into at least a portion of the annular space and displacingat least a portion of the drilling fluid from the annular space, whereinthe density and yield point of the spacer fluid are larger than thedensity and yield point of the drilling fluid, and wherein the spacerfluid comprises cement kiln dust (CKD), an organic acid, and water. 2.The method of claim 1, wherein the CKD has a specific gravity (SG) offrom about 2.6 to about 3.2.
 3. The method of claim 1, wherein the CKDhas a bulk density (BD) of from about 33 lb/ft³ to about 84 lb/ft³. 4.The method of claim 1, wherein the CKD has a water requirement (WR) offrom about 21 wt. % to about 100 wt. %.
 5. The method of claim 1,wherein the organic acid comprises tartaric acid, citric acid, oxalicacid, gluconic acid, oleic acid, uric acid, maleic acid, fumaric acid,acetic acid, octenyl succinic acid, dodecenyl succinic acid,aminotrismethylenephosphonic acid (ATMP), lactic acid, formic acid,oxalic acid, glyoxylic acid, glycolic acid, uric acid, amino acid,propionic acid, butyric acid, phthalic acid, malonic acid, oxaloaceticacid, benzoic acid, glucuronic acids, acrylic acid, malonic acid,tartronic acid, mesoxalic acid, dihydroxymalonic acid, pyruvic acid,hydracrylic acid, glyceric acid, glycidic acid, isobutyric acid,acetoacetic acid, malic acid, crotonic acid, valeric acid, iso-valericacid, glutaric acid, oxoglutaric acid, caproic acid, adipic acid,pyrocitric acid, isocitric acid, sorbic acid, enanthic acid, pimelicacid, salicylic acid, cinnamic acid, caprylic acid, phthalic acid,pelargonic acid, trimesic acid, carpric acid, sebacic acid, orcombinations thereof.
 6. The method of claim 1, wherein the organic acidmay be used at bottomhole circulating temperatures (BHCTs) in a range offrom about 50° F. to about 500° F.
 7. The method of claim 1, wherein theorganic acid is present in an amount of from about 0.01 wt. % to about10 wt. % based on a total solid weight of the spacer fluid.
 8. Themethod of claim 1, wherein a ratio of a weight of the organic acid toCKD is in a range of from about 0.5% to about 4%.
 9. The method of claim1, wherein the spacer fluid has a density in a range of from about 4lb/gal to about 23 lb/gal.
 10. The method of claim 1 wherein the spacerfluid is capable of remaining in a pumpable fluid state for at leastabout 4 hours.
 11. The method of servicing a wellbore of claim 1,further comprising placing a cementitious fluid into at least a portionof the annular space and displacing at least a portion of the spacerfluid from the annular space, wherein the density and yield point of thecementitious fluid are larger than the density and yield point of thespacer fluid.
 12. The method of claim 11, wherein the organic acidcomprise tartaric acid, citric acid, aminotrismethylenephosphonic acid(ATMP), or combinations thereof.
 13. The method of claim 1, wherein theorganic acid comprise tartaric acid, citric acid,aminotrismethylenephosphonic acid (ATMP), or combinations thereof. 14.The method of claim 13, wherein the CKD has a specific gravity (SG) offrom about 2.6 to about 3.2, wherein the CKD has a bulk density (BD) offrom about 33 lb/ft³ to about 84 lb/ft³, and wherein the CKD has a waterrequirement (WR) of from about 21 wt. % to about 100 wt. %.
 15. Themethod of claim 14, wherein the organic acid is present in an amount offrom about 0.01 wt. % to about 10 wt. % based on a total solid weight ofthe spacer fluid.
 16. The method of claim 15, wherein the organic acidmay be used at bottomhole circulating temperatures (BHCTs) in a range offrom about 50° F. to about 500° F.
 17. The method of claim 11, whereinthe cementitious fluid comprises a cementitious material, CKD, anorganic acid, and water.
 18. The method of claim 17, wherein thecementitious material comprises Portland cement, pozzolana cement,gypsum cement, shale cement, acid/base cement, phosphate cement, highalumina content cement, slag cement, silica cement, high alkalinitycement, magnesia cement, or combinations thereof.
 19. The method ofclaim 17, further comprising a supplementary cementitious material(SCM).
 20. The method of claim 19, wherein the SCM comprises Class F flyash, Class C fly ash, sand, shale, silica, zeolite, metakaolin, orcombinations thereof.